After a bit of reading into it, i am sure (dont hold me to it) but i think the only people who will be paying the £415 are the people with 06 registered cars that are still pumping out over 225g/km.
If you go here http://www.direct.gov.uk/en/Motoring/Ownin...icle/DG_4022118,
got down near the bottom of the page and open / download the pdf file called "‘Rates of vehicle excise duty' (V149) (PDF, 158K)"
It has 2 defining boxes, one stating "cars registered on or after 1st march 2001" price for us indicates £210 for us.
The 2nd box below it stating " cars registered on or after 23rd march 2006" Price for that indictes £400+